Water heater



Nov. 24, 1931. A. J. THOMAS WATER HEATER Filed Feb. 17, 1939 Patented Nov. 24, 1931 UNITED STATES ALVIN J. THOMAS, SAN FRANCISCO, CALIFORNIA WATER HEATER Application filed February 17, 1930. Serial No. 429,093.

My invention relates to improvements in water heaters wherein a gas burner is mounted axially within a heating coil and is arranged to project flame against the inner 3 surface of the coil at a plurality of vertically spaced points above the bottom turns of the coil to obtain a quick and efficient heating of water circulated through the coil.

, The primary object of my invention is to provide an improved water heater.

Another object is to provide an improved heater wherein heat is applied to the inner surface of a coil at vertically spaced points therealong to obtain an increased heating efficiency.

A further object is to provide an improved device of the character described wherein the heating means is arranged above the lowermost turns of a coil to prevent the deposit and caking of sediment within the coil.

Another object is to provide an improved water heater wherein a by-pass is connected between the inlet and outlet ends of the 0011 l. to provide a circulation of water adapted to '25 prevent the delivery of steam from the coil.

A further object is to provide an improved coil and burner structure and arrangement adapted to obtain increased heating area and to utilize a maximum amount of the heat from 80 the burner.

Another object is to provide an improved device wherein a burner is formed from a plurality of burner units connected in spaced axial alinement whereby the number of such units may be increased or decreased as desired without altering the relation of the units within a heating coil. 7 v

A still further object is to provide an improved water heater of simple and compact construction and which is simple and efiicient in operation.

I accomplish these and other objects by means of the improved device disclosed in the drawings forming a part of the present '50 Fig. 1 is a broken vertical section of my improved water heater, the coil and burner being shown partly in elevation;

Fig. 2 is a transverse section taken upon the line 2-2 of Fig. 1 in the direction in dicated;

Fig. 3 is a transverse section taken upon the line 33 of Fig. 1 in the direction indicated; and

Fig. 4 is a sectional detail of a burner unit, drawn upon a larger scale.

Referring to the drawings, the numeral 1 is used to designate in general a housing, preferably of cylindrical form and provided with a hingedly mounted door 2 movable to open and close the front of the housing. The lower end of the housing is substantially open and rests upon a suitable support 3. A cover 4 is mounted upon the top of the hous ing, said cover being provided with a Vent 6 opening outwardly from the housing to a suitable stack 7, preferably provided with a hood 8 arranged to prevent down draft into the housing.

A coil 9, formed from copper tubing, or other suitable material, is mounted Within the housing 1. The coil 9 extends vertically within the housing from the bottom to the top thereof, the exterior diameter of the coil being such as to afford a slight clearance between the coil and the wall of the housing. An inlet 11 is connected into the bottom of the coil and an outlet 12 connects into the top of the coil, said inlet and outlets preferably forming extensions of the coil extending laterally outward from the bottom and top of the housing respectively. The inlet and outlet are connected to a supply of water to be heated, said inlet and outlet preferably being connected to a boiler, not shown, at the bottom and near the top of said boiler respectively. A by-pass 14 is connected between the inlet 11 and outlet 12 at points outside of the housing 1.

A burner, designated in general by the numeral 16, is mounted within the coil 9. The burner 16 preferably comprises a manifold 17 provided with a plurality of burner units 18 axially spaced along the manifold. The units 18 preferably consists of sleevelike members each having a plurality of ra dial burner openings 19 as best shown in Fig. 4 of the drawings. The units are connected in axial alinement by means of nipples 21 threaded into the ends of adjacent units 18 and forming a continuation of the manifold from each burner'unit 18 to the next unlt whereby any desired number of burner units may be connected together in axial aline- .ment to receive fuel through a common manifold. The top of the manifold is closed by means of a cap 22. A rod'23 is connected at 1 lower end of the manifold 17 and fitting 26.

The fitting 27 preferably consists of a tubular member arranged in axial relation to the manifold and'with its upper or delivery end extending slightly upwardly into the fitting 26. Fuel, preferably gas, is delivered to the fitting 27 from a suitable source of supply through a supply connection 28 provided with a suitable valve 29 for controlling the supply of fuel. The lower end of the tubular fitting 27 extends downwardly from the fuel connection 28 to form a reservoir 30 to collect any moisture which may condense within the fitting 27. V

A plurality of baffles 31 are mounted across the coil 9 at vertically spaced points above the burner 17. The baffles preferably consist of flat metal plates having the corners thereof shaped to extent between adjacent turns of the coil 9 and support the plates across the coils. The plates 31 are apertured as at 32 to receive the supporting rod 23.

In operation, the heater is mounted with the inlet 11 connected into the bottom of a boiler or the like, and the outlet 12 connected into the top portion of the boiler, the bypass 14 being connected to the inlet and outlet between the coil 9 and said boiler. When fuel, issuing from the burner 16, is ignited, a fiame is directed from each burner opening 19 0f each burner unit 18 against the inner surface of the coil 9. The vertlcally spaced relation of the burner units 18 pro ect flame against the coil at correspondingly spaced elevations, thereby heating the causes the water to be heated very quickly and thereby causes a rapid circulation of water through the heater. The baffles 31 above the burner retard the escape'of heat directly to the vent 6, thereby causing a maxim m of 'or temperature changes.

the heat from the burner to be absorbed by the coil.

The lowermost burner unit 18 is arranged above the lowermost turns of the coil 9. This arrangement is particularly valuable as a means for preventing the caking of sediment upon the interior of the coil. While the water is in a static condition, any sediment present in the water tends to settle in the lowermost turns of the coil. When heat is applied directly upon tlie turns containing this sediment, the excessive'heat before circulation of water is started causes the sediment to cake upon the interior of the coil and thus retard the circulation and reduce the efficiency with which heat is absorbed. By positioning the lowermost burner unit above the lowermost coils, the heat is applied above the level of the accumulated sediment. The upward circulation caused when the burner is started causes a rapid upward circulation which carries the sediment out of the coil before said sediment is allowed to harden and cake, thereby effectually preventing the forming of cake within the coil.

The number of heating units 18 is varied according to the particular requirements of each installation. If the quantity of water to be heated is large, the number of burner .units is increased by adding one or more burner units 18 successively upon the upper end of the burner. v The relatively large area of heating surface subjected to direct action of the burner often tends toconvert the water within the coil 9 to steam before it passes outwardly through the outlet 12. The circulation of the water past the upper end of the by-pass 14 causes unheated water to be drawn through the by-pass, such water serving to absorb any steam delivered from the coil and to reduce the temperature of water from the coil sufficiently to prevent overheating of the water. If desired, the supply of fuel to the burner 17 may be automatically controlled by suitable mechanism'operated either by pressure Such mechanism, however, is well known and forms no part of the present invention and is therefore omitted from the disclosure herein made.

While I have illustrated what I regard as the preferred embodiment of my invention, various changes may be made in the specific details of construction, relative size, and arrangement, without departing from the spirit of my invention. I therefore desire to avail myself of all modifications which may fall within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. A water heater comprising a vertically disposed coil, having an inlet and an outlet at the top and bottom thereof respectively, connected to a supply of water to be heated;

a gas burner axially disposed within the coil and comp-rising a vertically disposed manifold provided with a plurality of burner units vertically-spaced therealong and each directing flame against the inner surface of the coil at spaced points therealong, the lowermost burner unit being positioned above the plane of the lowermost turns of the coil; a housing enclosing the coil and burner; a vent opening from the top of the housing to carry off products of combustion; and a burner supporting rod connected at its upper end to the top of the housing and extending axially downward through the coil into engagement with the top of the burner manifold.

2. A water heater comprising a vertically disposed coil, having an inlet and an outlet at the top and bottom thereof respectively, connected to a supply of water to be heated; a gas burner axially disposed within the coil and comprising a vertically disposed manifold provided with a plurality of burner units vertically spaced therealong and each directing flame against the inner surface of the coil at spaced points therealong, the lowermost burner unit being positioned above the plane of the lowermost turns of the coil; a housing enclosing the coil and burner; a vent opening from the top of the housing to carry off products of combustion; a burner supporting rod connected at its upper end to the top of the housing and extending axially downward through the coil into engagement with the top of the burner manifold; and a plurality of baffles mounted across the coil at vertically spaced points above the burner.

3. A water heater comprising a vertically disposed coil, having an inlet and an outlet at the top and bottom thereof respectively, connected to a tank of water to be heated; a gas burner axially disposed within the coil and comprising a vertically disposed manifold provided with a plurality of burner units vertically spaced therealong and each directing flame against the inner surface of the coil at spaced points therealong, the lowermost burner unit being positioned above the plane of the lowermost turns of the coil; a housing enclosing the coil and burner; a vent opening from the top of the housing to carry off products of combustion; a burner supporting rod connected at its upper end to the top of the housing and extending axially downward through the coil into engagement with the top of the burner manifold; bafiles mounted across the coil at vertically spaced points above the burner; and a by-pass connecting the inlet and the outlet of the coil at points between the ends of the coil and the tank.

In witness whereof, I hereunto set my signature.

ALVIN J. THOMAS. 

